The purpose of the research is to provide a fine-grained analysis of the effects of early visual experience on the development of discriminatory competence in infancy. The design involves experimental manipulation of the contingency conditions governing the infant's interaction with specific stimuli. Three-month-olds will be exposed to contrasting cues under a variety of discrimination training conditions differing in terms of (a) the provision of differential reinforcement, (b) the necessity for instrumental responding, and (c) the number of discriminative cues exposed. Following training, all infants will be given multiple discriminative tests in order to assess the degree and generality of the original learning. The findings should contribute to our understanding of the role of differential reinforcement and differential responding in facilitating early perceptual development, to the refinement of methodology for studying infant perception and learning, and, ultimately, to the establishment of an educational technology which is appropriate and viable early in life.